Reciprocating grate assembly for



' 12, 1939. v LA G NAD 2,183,457

RECIPROCATING GRATE ASSEMBLY FOR SELF-FEED MAGAZINE BOILERS Filed Sept. 12, 1938 I 2 tsSheet 1 a. 27 2b ")8 '59 Z4- 59 57 7 2'5 F5. E gwum Jigviwn (Zia @rerzzde,

Dec. 12, 1939. s.' J. LA GRENADE 2,183,457

RECIPROCATING GRATE ASSEMBLY FOR SELF-FEED MAGAZINE BOILERS Filed Sept. 12, 1938 2 Sheets-Sheet 2 Patented Dec. 12', 1939 UNITED STATES RECIPROCATING GRATE ASSEMBLY FOR SELF-FEED MAGAZINE BOILERS Stephen J. La Grenade, Cherry Creek, N. Y.

Application September 12, 1938, Serial No. 229,591

11 Claims.

The present invention relates to new and useful improvements in stoker furnaces and more particularly to grates adapted for use therein.

In magazine boilers of the self-feed type it has 6 heretofore been necessary to maintain a deep fuel bed upon the slanting grates in order to prevent unburnt coal from falling through the grates during an ash removal period. The reason therefor is attributed to the structure of the slanting grates presently known in the magazine feed boiler art. As the burning fuel slides over the slanting grates the consumed fuel or ash piles up and to operate the boiler with any degree of efficiency it is necessary to remove the ash at frequent intervals. The grates of the magazine self-feed boilers as known to the art are provided with grates which are raised centrally thus allowing the ashes to fall from the central portion of the fuel bed into the ash pit below. If a deep fuel 80 bed is not maintained such ash removal will cause unconsumed coal to fall into the ash pit along the ashes. The eflicient fuel consumption is thereby decreased. Furthermore, the ashes re mote from the central opening in the grate are 26 not removed with ashes overlying the said opening as they tend to slide away from rather than toward the point of ash precipitation. These ashes clog up the grates and prevent the free flow of air therethrough. As a result the fuel bed 80- does not receive the proper draft for the efficient consumption of the coal and the bed has to be frequently agitated in an attempt to at least keep the central portion of the fuel bed conditioned for the requisite air fiow. This frequent manual 86 agitation of the fuel bed is a considerable nuisance and at the same time it requires a skillful operator to keep the unburnt coal from falling into the ash pit during the agitation period. With each agitation the fuel bed is completely broken With these disadvantages in mind it is an object of the present invention to provide reciprocating grates for a stoker furnace in which the ashes are removed from the fuel bed from every 45 point, overlying the grates.

Another object is to provide reciprocating grates which extend transversely of both the slanting fuel bed and the underlying ash pit.

Still another object is to provide a stoker fur- 60 nace which automatically precipitates the ashes from the bottom of the fuel bed at selectively timed intervals.

A further object is to provide a stoker furnace having a plurality of reciprocating grates in 56 which adjacent grates move simultaneously in an opposite transverse direction across the slanting fuel bed.

Another object is to provide front and rear lateral grates and a bottom grate which extend upwardly from a plurality. of fuel bed grates and 5 move simultaneously therewith.

Yet another object is to provide a plurality of fuel bed grates having similar grates lying thereover, and adjustably attached thereto for movement therewith. 10

Another object is to provide a plurality of reciprocating fuel grates, the openings in each of which can be selectively adjusted.

Another object is to provide an automatically operated self-feed magazine boiler having a plurality of grates all of which simultaneously reciprocate at timed intervals.

Another object is to provide a stoker furnace having a shallow evenly distributed coal bed and in which the said coal bed remains comparatively undistributed during an ash removal period.

Other and further objects and advantages of this invention will be apparent from the following specification and from the claims appended hereto.

In the drawings wherein like numerals refer to corresponding parts throughout the several views:

Figure 1 is a plan view of the inclined grates of a self-feed magazine boiler and embodies the features of the invention,

Figure 2 is a sectional view taken along the line 2--2 of Figure 1, illustrating the grate assembly,

Figure 3 is a sectional view taken along the line 3-3'of.Figure 2, q

Figure 4 is an enlarged detail of one of the grates of the self-feed magazine boiler, and

Figure 5 is an enlarged sectional detail taken along the line 4-4 of Figure 4 and illustrating the adjustable attachment of an auxiliary grate.

Referring now to the drawings and more particularly to Figures 1 and 2, the numeral ID indicates a casing composed of any fire resistant material and provided with'an ash door in the front thereof and enclosing an ash pit P. The side walls of the casing ID are recessed at the upper portions thereof to receive a front grate I l and a rear grate [2 which are adapted to slide backward and forward in the recesses. The

grates II and I2 have bifurcated arms l3 secured g at one end thereof which in turn has an arm l9 offset therefrom substantially parallel to the axis of the crank H. The arm I9 is securely supported by a bracket 2i which is securely bolted or otherwise fastened to the casing or housing 90. The arm i9 is provided at the end thereof with a bearing 2! which is adapted to receive a lever arm to manually turn the crank ll backwards and forwards.

The crank I! is provided at the other end thereof with an offset arm 22 having an arm 23 projecting therefrom substantially along the axis of arm 19. The arm 23 is rotatably supported by bracket 24 made of metal or the like which is securely bolted to a strong wood or metal plank 25 which in turn is bolted or otherwise fastened to the housing ID. A bevel gear 26 is mounted on the outer end of the arm 23 and engages a bevel gear 2'5 which is mounted on one end of a second crank shaft 25 which is journalled in an opening through the outer end portion of the plank 25 and is supported thereby. The other endof said crank 28 is journalled through and adapted to turn in an opening in the outer end portion of a metal or like member 29 which is securely fixed to the housing it and. is supported thereby. The crank 23 has a sprocket member 38 secured to the other end thereof. Said sprocket member 36 is connected to a rotatable member 3! of the back geared electric motor M by a cog. chain 32. The motor M is Wiredly connected to an automatically operated time device such as clock T and its. operation is controlled thereby. The motor M only operates at selected time intervals. The motor M and the clock T in themselves constitute no part of the present invention and are to be considered only in combination. with the self-feed magazine boiler assembly.

Extending transversely across the ash pit P are a plurality of inclined fuel bed grates 33, 34, 35 and 36 each provided with a plurality of laterally projecting teeth in spaced apart relation, and preferably become narrower in width from the first grate 33 to the last grate 3G. The grates 33, 3 35 and 36 extend beyond thehousing is at the front and rear walls thereof and are provided each with a bifurcated arm 31 at one end which receives the recessed end: portion of a link 38 which is secured: to the arm .il'by a bolt 39. The links 38 are each provided at the other ends thereof with a bearing 40 through which the crank shaft 23 is journaled and is adapted to turn therein. The crank 28 is of the usual type and has offset portions indicated at 2811 at spaced intervals along the shaft. The grates 33, 3 3, 35 and 36 are preferably connected to the crank 28 and the offset portion- 28a by the links 38 at spaced distances throughout the length thereof so that movement of the crank causes alternate grates to simultaneously move in the same direction. For example, grates 33 and 35 would move in one direction across the ash pit P while grates 34 and 35 move in the opposite direction.

The grates 33, 34, 35 and 36 are further provided in the outer end portions thereof each with longitudinal slots M and 42. An auxiliary nest of grates 33a, 36b, 35c and 36d are superimposed upon the fuel bed grates 33, 34, 35 and 36 and have'slots Ma and 42a in the outer ends thereof which coincide with the longitudinal slots 4! and G2. The auxiliary grates 33a, 34b, 35c and 36d are secured to the fuel bed grates by bolts or the like which fit through slots 4| and Ma and the slots '62 and-42a. The auxiliary grates are adjustably slidable over the fuel bed grates so that the openings between the spaced apart teeth on the fuel bed grates can be made selectively larger or smaller depending upon the size of the coal used in the boiler, and the size of the fuel ash as it progressively slides down the inclined grates.

Adjacent to and extending upwardly from grates 36 andtfid is a bottom grate 43 which is substantially perpendicular to the front grate i! and the rear grate l2 and which is adapted to reciprocate therebetween. A tie rod 44 connects the bottom grate 43 to the underneath side of fuel bed grate 35 and "when in operation the grates li and 35 have the same directional motion.

A magazine or hopper H is positioned over the upper fuel bedgrate 3'3 and the auxiliary grate 33a at a point preferably above the laterally projecting spaced apart teeth. The hopper H is provided with a throat 1. through 'which'the coal is automatically gravity fed uponthe inclined grate assembly. Reciprocatory motion of the upper grates 33 and 33a keep the coal from fusing in the throat t and starts the coal on its movement downwardly over the live fuel bed. The grates 33 and 33a have a solid upper section over which the throat t of the hopper H is positioned. This prevents air from passing through the throat t into the hopper H and keeps the coal from burning in the said hopper or magazine.

In operation, the coal feeds through the hopper and progressively over the inclined grates. The clock T is set for operation at a selected time interval. At a prearranged time the clock T will set the backgeared electric motor M into operation. The, drive member 3! will rotate the sprocket member 36 through the chain 32 which in turn simultaneously and automatically operates the cranks 28 and H and reciprocates the.

front grate H, the rear grate l2, the bottom grate 43, and the fuel bed grates 33, 34, 35 and 36 along with the adjustable auxiliary grates 33a, 3.42),.350 and 36d. The front grate H and the rear grate i2 in reciprocating at timed intervals keep the side of the boiler free from ashes and keep the fuelbed from bridging over the; fuelbed grates. At the same time they permit airv to freely enter into the fuel bed area to promote emcient combustion. Each adjacent fuel bed grate moves simultaneously in the opposite direction and will break up any caked ashes or clinkers and grate ofi the bottom of the fuel bed without. disturbing it.

The fuel bed grates can be adjusted by proper arrangement of the overlying auxiliary grates. The grates nearer the hopper are preferably adjusted with small spaces between the grate teeth so that the unburned coal will not fall into the ash pit. The openings between the grates are preferably enlarged as they become more remote Further modifications, particularly in the. are

rangement and directionof movement of the grates, will be apparent to those skilled in the art and it is desired, therefore, that the invention be limited only by the scope of the appended claims.

I claim:

1. In a self-feed magazine boiler provided with an ash pit, a plurality of inclined reciprocating grates extending transversely across said ash pit, and substantially transversely to the direction of motion of the fuel bed which is adapted to travel downwardly thereover, a plurality of auxiliary grates overlying said first mentioned grates and adjustably secured thereto to provide adjustable openings in the said grates over which the fuel travels, a front grate extending upwardly from said auxiliary grates and transversely of their longitudinal axes, a rear grate spaced apart from said front grate and substantially parallel therewith, a bottom grate extending upwardly from one of said auxiliary grates between said front and rear grates,

and means to simultaneously operate all of said grates.

2. In a self-feed magazine boiler provided with an ash pit, a plurality of inclined reciprocating fuel bed grates extending transversely across said ash pit, and substantially transversely to the direction of motion of the fuel bed which is adapted to travel downwardly thereover, a front grate extending upwardly from said fuel bed grates and substantially transverse to the longitudinal axes thereof, a rear grate extending upwardly from said fuel bed grates and substantially parallel to said front grate, a bottom grate extending upwardly from one of said fuel bed grates between said front and rear,

grates, and means to simultaneously operate all of said grates.

3. In a self-feed magazine boiler provided with an ash pit, a plurality of inclined reciprocating grates extending transversely across said ash pit and substantially transversely to the direction of motion of the fuel bed which is adapted to travel downwardly thereover, a plurality of auxiliary grates overlying said first mentioned grates and adjustably secured thereto to provide adjustable openings in the said grates over which the fuel travels, a front grate extending upwardly from said auxiliary grates and substantially transversely of their longitudinal axes, a rear grate spaced apart from said front grate and substantially parallel therewith, a bottom extending upwardly from one of said auxiliary grates between said front and rear grates, and power means to automatically operate all of said grates simultaneously.

4. In a self-feed magazine boiler provided with an ash pit, a plurality of inclined reciprocating fuel bed grates extending transversely across said ash pit and substantially transversely to the direction of motion of the fuel bed which is adapted to travel downwardly thereover, a front grate extending upwardly from said fuel bed grates and substantially across the longitudinal axes thereof, a rear grate extending upwardly from said fuel bed grates and substantially parallel to said front grate, a bottom grate extending upwardly from one of said fuel bed grates between said front and rear grates and operatively connected to one of said fuel bed grates, and power means to automatically operate all of said grates simultaneously.

5. In a self-feed magazine boiler provided with an ash pit, a plurality of inclined reciprocating fuel bed grates extending transversely across said ash pit and substantiallytransversely to the direction of motion of the fuel bed which is adapted to travel downwardly thereover, a-plurality of auxiliary grates overlying said fuel bed grates and adjustably secured thereto to provide adjustable openings in the said grates over which the fuel travels, a front grate extending upwardly from said fuel bed grates and across the longitudinal axes thereof, a rear grate spaced from said front grate and parallel thereto, and means to simultaneously operate all of said grates.

6. The structure of claim 5 with power means to automatically operate all of said'grates at the same time.

7. In a self-feed magazine boiler provided with fuel bed grates extending transversely to the direction of motion of the fuel bed which is adapted to travel thereover, a plurality of auxiliary grates overlying said fuel bed grates and adjustable openings in the said grates over which the fuel travels, each adjacent auxiliary grate being adapted to simultaneously move in an opposite direction, a front grate extending upa fuel bed, a plurality of inclined reciprocatory 1 wardly from said auxiliary grates and across the p I longitudinal axes thereof a rear grate spaced from said front grate and parallel thereto, a bottom grate extending upwardly from one of said auxiliary grates and between said front and rear grates, said bottom grate being operatively secured to a fuel bed grate once removed therefrom, and means to simultaneously reciprocate all of said grates.

8. A reciprocating grate assembly comprising,-

vided with slots cooperating with the slots of one ofsaid fuel bed grates to provide openings of increasing area from the point of fuel inlet to the point of fuel discharge, said fuel bed grates and said auxiliary grates extending transversely to the direction of motion of a fuel bed which is adapted to move downwardly thereover, and

means to reciprocate said grates.

9. A reciprocating grate assembly comprising, a plurality of inclined fuel bed grates provided with slots in spaced apart relation, a plurality of auxiliary grates each of which overlies one of said fuel bed grates and is adjustably secured thereto, said auxiliary grates each being provided with slots cooperating with the slots of one of said fuel bed grates to provide openings: of increasing area from the point of fuel inlet to the point of fuel discharge, said fuel bed grates. and said auxiliary grates extending transversely to the direction of motion of a fuel bed which is adapted to move downwardly thereover,, and power means to automatically reciprocate said grates simultaneously. 7

10. A reciprocating grate assembly comprising a plurality of inclined fuel bed grates provided the direction of motionof a fuel bed which is 75 adapted to move downwardly thereover, a front grate extending upwardly from said auxiliary grates and across the longitudinal axes thereof, a rear grate spaced from said front grate and parallel thereto, a bottom grate extending upwardly from one of said auxiliary grates and disposed between said front and rear grates, and means to simultaneously reciprocate all of said rates.

11. A reciprocating grate assembly comprising a plurality of inclined fuel bed grates provided with slots in spaced apart relation, a plurality of auxiliary grates each of which overlies one of said fuel bed grates and is adjustably secured thereto, said auxiliary grates each being provided with slots cooperating with the slots of one of said fuel bed grates to provide openings of increasing area from the point of fuel inlet to the point of fuel discharge, said fuel bed grates and said auxiliary grates extending transversely to the direction of motion of a fuel bed which is adapted to move downwardly thereover, a front grate extending upwardly from said auxiliary grates and across the longitudinal axes thereof, a rear grate spaced from said front grate and parallel thereto, a bottom grate extending upwardly from one of said auxiliary grates and disposed between said front and rear grates, and power means to automatically reciprocate all of said grates simultaneously.

STEPHEN J. LA GRENADE. 

